SEMAT Cleaning up the Confusion, Jargon and

Fads of Software Engineering

Chuck Connell, chc-3.com

Introduction Software design/development

consultant in Bedford, MA Lotus/IBM previous to consulting Instructor of software engineering at

BU Author of recent book Beautiful

Software› Topics related to this talk and other issues› Two giveaways

Outline A problem in software engineering What SEMAT is and how they are trying

to solve the problem An example from my work, in the spirit

of SEMAT Analysis: SEMAT successes and

warnings

A quote…. “Software engineering is gravely hampered today by immature

practices. Specific problems include:

› The prevalence of fads more typical of fashion industry than of an engineering discipline.

 › The lack of a sound, widely accepted theoretical basis. › The huge number of methods and method variants, with differences

little understood and artificially magnified.

› The lack of credible experimental evaluation and validation. › The split between industry practice and academic research. “

Do you agree? Feedback from roundtable?

I agree… Fads

› Structured A/D (1980), CMM (1990), object oriented A/D (1995), open source (2000), agile (2005), more…

Freebie: who wrote seminal book on SD? Method overload

› CMM vs. ISO 9126 RAD vs. agile› Key similarities, differences?

Lack of theory› Why does refactoring work?

A Scary Picture Credit to Sarah Sheard in Evolution of

the Frameworks Quagmire. 2001/2003, but still relevant

PSP

IEEE/EIA 12207

Baldrige

ISO/IEC 15504

People CMM

IPD-CMM*

SECAM

SCE

MIL-STD- 498

DOD-STD-

2167A

MIL-STD499B*

ISO/IEC

12207IEEE1220

SDCE

SE-CMM

EIA731

EIA/IS 632

ISO 9000

series

Ansi/EIA 632

SSE-CMM

ISO/IEC 15288

CMMI

SA-CMM

Q9000

DOD-STD-2168

FAA-iCMM#

RTCA DO-178B

SW-CMM

TL9000

ISO 1593

9PSM

SCAMPI

CBA IPI

SAM

FAM**

Process StdsQuality StdsMaturity or Capability

ModelsAppraisalmethods

Guidelines

Six Sigma

J-STD016

DOD-STD-

7935ATSP

The Frameworks Quagmire

So What is SEMAT? Software Engineering Method and Theory Organization dedicated to fixing these

problems Started in 2009 with 3 articles in DDJ by

Ivar Jacobson, Bertrand Meyer and Richard Soley

Now 30 famous people + 15 major institution “signatories”, and 1600 “supporters”

SEMAT Mission “We support a process to re-found software

engineering based on a solid theory, proven principles and best practices that:

› Include a kernel of widely-agreed elements, extensible for specific uses

 › Addresses both technology and people issues › Are supported by industry, academia, researchers and users › Support extension in the face of changing requirements and

technology”

An Improved PictureAll of SWE expressible from…

Methods

PatternsPractices

Kernel: universals + language

This Would Be a Big Deal! Describe all current SWE methods with a

common language and concepts Know that ABC method is a superset of

XYZ Know that ISO-1234 just a restatement of

CMM-AB Easily describe new process for new

situation Like discovery of DNA and the A-T-C-G

language of genetics!

Example: Refactoring But what could SEMAT look like in

practice? A possible example, from my own

work… Goal is universal sw design principles

› Could serve as foundation for all analysis/design methods

Freebie: what is source code refactoring?› Hint: two key aspects

Refactoring Example temp = 2 * (_height + _width); ‘perimeter

System.out.println (temp); temp = _height * _width; ‘areaSystem.out.println (temp);

› What is the problem(s) with this code?› Solution: Split Temporary Variable

perimeter = 2 * (_height + _width);

System.out.println (perimeter); area = _height * _width;System.out.println (area);

So What? Programmers have been tweaking code

since 1950. Disciplined, correct refactoring has at

least three benefits.› Successive, small changes can produce

BIG improvements.› Lightens the load on design phase.› More realistic design phase.› (Latter two support agile methods.)

But Refactoring is Ad-Hoc Unanswered questions…

1. When should you refactor? When is source code “not good” so it needs

improvement?2. Which refactoring method to use?

At least 70, several for each case. Some contradict each other.

3. Why is the change an improvement? No explanation for what is happening.

Current Answers No Good Summarizing thousands of pages of

research…1. A section of source code should be refactored

when it “smells bad.”2. We should apply the refactoring that helps with

this smell.3. No one knows.

We need a theory of refactoring.› What is refactoring?› Why does some code smells bad?› Why does refactoring make code better?

My Proposal 7 universal principles of good sw design

› Cooperation. Work well with its surrounding environment.

› Appropriate form. Form follow function. › Minimality. As small as it can be.› Singularity. Contain one instance of each

component. › Locality. Place related items together. › Visibility. Built-in clarity plus comments. › Simplicity. Solve its problems in the simplest

manner possible.

A Theory of Refactoring This theory answers the open

questions1. You should refactor when one/more of the

7 tenets are broken. 2. Use the transformation that most easily

reestablishes good design where it is currently broken.

3. Refactoring works by bringing software more in line with 7 principles.

What the Theory Give Us There are not 70 transformations, there

are only 7!› The 7 can be combined in various ways.› By Occam’s Razor, this is much better.

In the spirit of chemistry and physics.› Substances elements particles.

Predicts new transformations.› The best way to test any theory.

As With Any Theory… Needs evidence and arguments. Could be improved over time. But is within the spirit of SEMAT by

offering an overall theory of software design .

SEMAT Successes There is a clear problem.

Solution would obviously be useful Many important people are behind the effort

Lots of “working together” Have had 3 int’l conferences, each with report Broken into 6 tracks

› Requirements› Universals› Assessment› Theory› Kernel language› Definitions› Architecture (spike)

SEMAT Successes Goal is to improve practice not just create abstract results Foundation (kernel + language) acceptance transferred to

OMG in June 2011› So SEMAT is not voting on its own work› SEMAT is now one org that can propose solutions for problem it

defined 20 people working on kernel since March 2010.

› 8 universals proposed: opportunity, stakeholder community, requirement, software system, work, team, method, practice

Want to remove split between process nazies and programmers› Good!

SEMAT Problems Lots of discussion, few results

› 1p problem statement 20p vision 44p RFP

RFP actually a step backwards› It is a “request for” a result, not a proposal

Could become more jargon on top of existing jargon

… a “method” must be enactable, while a “practice” in isolation will in general not be. In the context of this RFP, the enactment of a method can be defined as the carrying out of that method in the context of a specific project effort. Within this context, the practices within the method may be considered use cases for the work that must be carried out to achieve the project objectives, with each practice providing a specific aspect of the overall method.

SEMAT Problems Need to watch for agile bias

Agile is FOTM, something else in 2020 SEMAT must define earlier flavors and next

Need to watch for cult of personality› Trumpet names/# of famous signatories› But science is about evidence, prediction,

internal consistency; doesn’t matter who says it

› History of science shows famous people are wrong about the next breakthrough

SEMAT Problems This has all been tried before!

› System Process Engineering Meta-Model (SPEM)› ISO/IEC 24744› Eclipse Process Framework› Software Engineering Body of Knowledge

(SWEBOK)› Unified Method Framework› More….

The RFP says each is inadequate› Worth a raised eyebrow though

Questions / Comments Questions? Comments?

For more information… SEMAT home page

› semat.org SEMAT vision statement

› www.semat.org/pub/Main/WebHome/SEMAT-vision.pdf

SEMAT blog› sematblog.wordpress.com/

My home page› chc-3.com

My book, including these issues› www.amazon.com/dp/1456438786/